Editing Selfish genetic element (section)

=== Speciation ===
Selfish genetic elements have been shown to play a role in [[speciation]].<ref name=":9" /><ref name=":10" /><ref>{{cite journal | vauthors = Patten MM | title = Selfish X chromosomes and speciation | journal = Molecular Ecology | volume = 27 | issue = 19 | pages = 3772–3782 | date = October 2018 | pmid = 29281152 | doi = 10.1111/mec.14471 | bibcode = 2018MolEc..27.3772P | s2cid = 20779621 }}</ref> This could happen because the presence of selfish genetic elements can result in changes in morphology and/or life history, but ways by which the co-evolution between selfish genetic elements and their suppressors can cause reproductive isolation through so-called [[Bateson–Dobzhansky–Muller model|Bateson–Dobzhansky–Muller incompatibilities]] has received particular attention.

An early striking example of hybrid dysgenesis induced by a selfish genetic element was the ''P'' element in ''Drosophila''.<ref>{{cite journal | vauthors = Engels WR | title = The origin of P elements in Drosophila melanogaster | journal = BioEssays | volume = 14 | issue = 10 | pages = 681–6 | date = October 1992 | pmid = 1285420 | doi = 10.1002/bies.950141007 | s2cid = 20741333 }}</ref><ref>{{cite journal | vauthors = Kidwell MG | title = Evolution of hybrid dysgenesis determinants in Drosophila melanogaster | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 80 | issue = 6 | pages = 1655–9 | date = March 1983 | pmid = 6300863 | pmc = 393661 | doi = 10.1073/pnas.80.6.1655| bibcode = 1983PNAS...80.1655K | doi-access = free }}</ref> If males carrying the ''P'' element were crossed to females lacking it, the resulting offspring suffered from reduced fitness. However, offspring of the reciprocal cross were normal, as would be expected since [[Piwi-interacting RNA|piRNAs]] are maternally inherited. The ''P'' element is typically present only in wild strains, and not in lab strains of ''D. melanogaster'', as the latter were collected before the ''P'' elements were introduced into the species, probably from a closely related ''Drosophila'' species. The ''P'' element story is also a good example of how the rapid co-evolution between selfish genetic elements and their silencers can lead to incompatibilities on short evolutionary time scales, as little as within a few decades.<ref name=":9" />

Several other examples of selfish genetic elements causing reproductive isolation have since been demonstrated. Crossing different species of ''Arabidopsis'' results in both higher activity of transposable elements<ref>Josefsson C, Dilkes B, Comai L. Parent-dependent loss of gene silencing during interspecies hybridization. Curr Biol. 2006;16: 1322–1328.</ref> and disruption in imprinting,<ref>{{cite journal | vauthors = Walia H, Josefsson C, Dilkes B, Kirkbride R, Harada J, Comai L | title = Dosage-dependent deregulation of an AGAMOUS-LIKE gene cluster contributes to interspecific incompatibility | journal = Current Biology | volume = 19 | issue = 13 | pages = 1128–32 | date = July 2009 | pmid = 19559614 | pmc = 6754343 | doi = 10.1016/j.cub.2009.05.068 | bibcode = 2009CBio...19.1128W }}</ref> both of which have been linked to fitness reduction in the resulting hybrids. Hybrid dysgenesis has also been shown to be caused by centromeric drive in barley<ref>{{cite journal | vauthors = Sanei M, Pickering R, Kumke K, Nasuda S, Houben A | title = Loss of centromeric histone H3 (CENH3) from centromeres precedes uniparental chromosome elimination in interspecific barley hybrids | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 108 | issue = 33 | pages = E498–505 | date = August 2011 | pmid = 21746892 | pmc = 3158150 | doi = 10.1073/pnas.1103190108 | doi-access = free }}</ref> and in several species of angiosperms by mito-nuclear conflict.<ref>{{cite journal | vauthors = Rieseberg LH, Blackman BK | title = Speciation genes in plants | journal = Annals of Botany | volume = 106 | issue = 3 | pages = 439–55 | date = September 2010 | pmid = 20576737 | pmc = 2924826 | doi = 10.1093/aob/mcq126 }}</ref>